High-dynamic range (HDR) and wide-color gamut (WCG) contents become more and more popular in broadcasting industries. User-end displays, however, only have limited color volume capacities. As an example, international telecommunication union (ITU) broadcast television 2020 (ITU-BT.2020) gamut is widely adopted in color grading by HDR contents creators. The gamut covers 75.8% commission on illumination (CIE) 1931 (CIE-1931) color space. But an HDR television (TV) with digital cinema initiatives (DCI) P3 (DCI-P3) gamut only covers 53.6% CIE-1931 space. Still widely existing standard dynamic range (SDR) TVs (SDR-TVs) with ITU-BT.709 gamut only covers 35.9% CIE-1931 space. Directly displaying the WCG contents on a user-end display may lead to serious hue/saturation distortions and high-visual impacts due to the out-of-gamut (OOG) colors. An effective color-gamut transferring (CGT) method is necessary to rendering WCG contents well on user-end displays.
Conventional CGT technologies cannot satisfy the fast developing HDR broadcasting/distribution markets. The simple and economic gamut clipping based techniques such as the color-space conversion (CSC) based CGT are low-cost, but may generate serious artifacts in converted colors, including clipping halos/edges, salt-pepper spots, or loss of details. High-performance color gamut mapping (CGM) and compression (CGC) techniques generally can obtain visually pleasing colors, but these are mostly based on color-appearance models, which require many complex and non-linear computations such as trigonometric or exponential calculations involved. This makes the CGM/CGC techniques very complex and computationally expensive. Therefore, those techniques are seldom adopted in industrial products.